Derived from tropical Cymbopogon grass, citronella has been a go-to natural insect repellent for centuries, leading many to wonder: does citronella repel gnats? While this aromatic plant contains powerful compounds like citronellal, geraniol, and citronellol that naturally deter various insects, its effectiveness against gnats isn’t quite so straightforward.
Primarily acting as a spatial repellent, citronella creates “zones” of reduced insect activity rather than providing complete protection. Your success with citronella for gnats may vary depending on factors like airflow, product quality, and even the specific type of gnats you’re dealing with. In this guide, you’ll discover the science behind citronella’s repellent properties and learn practical ways to maximize its effectiveness against gnats.
The Science Behind Citronella and Gnats
Image Source: Anveya
The efficacy of citronella against gnats comes down to a fascinating interplay between plant chemistry and insect biology. Understanding this relationship helps explain when and why citronella for gnats works, and when it might fall short.
What makes citronella a potential repellent
Citronella doesn’t kill gnats. Instead, it creates an environment they prefer to avoid. The oil works primarily by masking scents that attract gnats to you [1]. When you use citronella products, they emit volatile compounds that interfere with a gnat’s ability to locate their target. This masking effect essentially makes you “invisible” to these pesky insects.
Additionally, citronella can disrupt the sensory receptors that gnats use to find their next meal. This interference makes it difficult for them to detect the carbon dioxide, body heat, and other chemical signals that would normally lead them straight to you [2].
How gnats detect and respond to scents
Gnats navigate their world primarily through chemical sensing. These tiny insects possess sophisticated chemoreceptors, or specialized sensory organs that allow them to detect and differentiate between various scents [3].
For most gnat species, their feeding and egg-laying behaviors depend heavily on their olfactory response. Interestingly, studies have shown that different terpenes (plant compounds) can trigger varied responses in gnats. Some act as attractants, others as repellents [3].
Citronella appears to work against gnats because it interferes with their ability to detect the smells they’re naturally drawn to. Research has found that certain compounds in citronella can directly activate specific receptors in insects, triggering avoidance behavior [3].
Active compounds in citronella that affect gnats
The repellent power of citronella comes from its rich concentration of bioactive compounds, particularly:
Citronellal – The primary active component that makes up approximately 21.59% of Java citronella oil [4]. This compound can directly activate certain sensory pathways in insects, prompting avoidance behavior.
Geraniol – Found in higher concentrations (around 34.27%) in quality citronella oil [4], this compound contributes significantly to citronella’s repellent properties.
Citronellol – Present at around 7.43% [4], this alcohol works together with other compounds to enhance repellent effects.
These compounds work together to create citronella’s distinctive aroma. Laboratory research confirms that citronellal can activate specific receptors (TRPA1) in insects, influencing their feeding and avoidance behaviors [3]. Furthermore, citronella oil creates a vapor barrier that discourages gnats from entering treated areas [5].
Most notably, the repellent capacity represents citronella’s primary mode of action against gnats, making plants and environments treated with it less detectable and less appealing to these persistent pests [5].
Different Forms of Citronella: Which Works Best for Gnats?
Image Source: The New York Times
When it comes to keeping gnats away, citronella comes in various forms—each with its own strengths and limitations. Understanding which type works best can make the difference between a peaceful outdoor gathering and constant swatting.
Citronella candles: effectiveness and limitations
The classic citronella candle offers modest protection against gnats. In controlled studies, citronella candles showed approximately 29% repellency against mosquitoes [6], with similar limited effectiveness against gnats. Although convenient, these candles have significant drawbacks.
First, the smoke must physically pass between you and approaching gnats to work [7]. Additionally, most commercial candles contain only about 5% citronella concentration [8], which simply isn’t enough for reliable protection. And windy conditions significantly reduce their effectiveness [9].
Citronella plants as natural deterrents
Living citronella plants (sometimes called “mosquito grass”) can be more effective than manufactured products. The Brooklyn Botanic Garden recommends lemon-scented plants, including citronella grass, as natural deterrents [10].
These clump-forming perennials release their protective oils when brushed against, creating an immediate aromatic barrier. But a single plant offers minimal coverage – you’ll need strategic placement of multiple plants around seating areas for noticeable results.
Citronella oils and sprays: concentration matters
For direct application, citronella oils and sprays offer more targeted protection. However, concentration is crucial. Studies show that 100% citronella oil can provide complete protection against some insects for up to 120 minutes [11], yet diluted formulations last significantly less time.
Research indicates that even 10% citronella oil emulsions only protect for about 30 minutes [12]. For optimal results, look for products with clearly listed potency levels [13] and be prepared to reapply frequently.
Citronella-infused products: wristbands, torches, and more
Beyond the basics, numerous citronella-infused products aim to provide convenient protection. Wristbands infused with citronella claim to repel gnats for up to 200 hours [14], although actual effectiveness varies considerably. Tiki torches can create wider protection zones [15], primarily because they typically use higher concentrations of oil.
Still, many alternatives outperform traditional citronella. Studies found that candles containing 5% geraniol were approximately five times more effective than citronella candles at repelling biting insects [6]. Likewise, products containing oil of lemon eucalyptus generally offer better protection than citronella-based options [8].
Real Results: What Research Says About Citronella and Gnats
Research tells a more nuanced story about citronella’s effectiveness against gnats than product labels might suggest. Looking beyond marketing claims reveals important insights about when and how citronella actually works against these persistent pests.
Scientific studies on citronella’s effectiveness
Laboratory research shows citronella provides some protection against gnats, but with significant limitations. According to controlled studies, citronella demonstrates modest efficacy in deterring gnats such as biting midges [2]. In direct comparisons, citronella oil’s protection time falls significantly shorter than DEET-based repellents, with a difference of approximately 253 minutes [16].
Indoor testing reveals that citronella diffusers achieve about 68% repellency against flying insects, whereas citronella candles manage only 14% repellency [17]. Outdoor performance drops further, with diffusers placed 6 meters from traps showing just 22% repellency [17].
Factors affecting citronella performance outdoors
Several key elements influence how effectively citronella repels gnats in real-world settings:
Concentration levels – Products containing 5-10% citronella typically provide protection for up to 2 hours maximum [18]
Application method – Continuous release diffusers outperform candles substantially [17]
Environmental conditions – Wind speed and ambient temperature directly impact dispersal [1]
Formulation quality – Adding vanillin to citronella can significantly extend protection time [16]
Citronella’s bug-repelling power fades fast—usually within an hour because its active ingredients evaporate quickly. But thanks to microencapsulation (a method that slowly releases those ingredients over time), newer formulas can keep working for several hours.
How different gnat species respond to citronella
Not all gnats react identically to citronella. For instance, biting midges (Culicoides) show variable responses – some species avoid citronella-treated areas [20], yet Culicoides imicola may actually be attracted to citronella under certain conditions [1].
Field studies on plant-damaging gnat species found citronella oil decreased ant attacks and scarring symptoms on fruits [21]. Interestingly, citronella functions in multiple ways: as a contact repellent, feeding deterrent, and occasionally as a direct toxin causing damage to insect integument [21].
Maximizing Citronella’s Effectiveness Against Gnats
Image Source: | illuminate your world with the magic of candles
Struggling to get citronella to actually work against gnats? Despite mixed research results, you can significantly boost citronella’s effectiveness by using it correctly. Getting the most from citronella requires strategic application and understanding its limitations.
Proper placement for optimal coverage
Strategic positioning makes all the difference when using citronella for gnats. Place citronella sources near entry points where gnats typically invade your space [13]. Doorways, windows, and patio perimeters deserve special attention. During outdoor gatherings, position citronella candles or torches upwind, allowing the scent to drift across your seating area [3].
Airflow plays a crucial role – use fans to help disperse citronella’s aroma throughout larger spaces [13]. For citronella plants, position them along walkways where you’ll naturally brush against them, releasing their oils [5].
Combining citronella with complementary scents
Citronella works better with friends! Boost its effectiveness by combining it with other insect-repelling essential oils. Peppermint, lavender, and eucalyptus oils make particularly powerful partners [22]. These combinations create a more potent repellent blend that offers extended protection against gnats.
For DIY spray repellents, combine citronella with other essential oils while keeping the total concentration under 15% for safety [23]. Despite its limitations, citronella becomes much more effective when paired with vanillin, extending protection time up to three hours [24].
When and how to reapply citronella products
Firstly, understand that citronella has a shorter effective period than synthetic alternatives – requiring more frequent reapplication [27]. Most citronella products provide protection for no more than 2-3 hours before needing refreshing [13].
If using citronella, plan reapply every 1-2 hours, especially after swimming or sweating [28]. Quality matters significantly – choose concentrated citronella formulas with clearly stated potency levels rather than diluted products [13].
The Final Verdict on “Does Citronella Repel Gnats?”
Though citronella might not be the miracle gnat repellent some claim, it still deserves a place in your pest control toolkit. Scientific research confirms its ability to deter gnats, albeit with important limitations. Success depends largely on proper application methods and realistic expectations.
Keep in mind that citronella works best when reapplied regularly and used under the right conditions. While it may not last as long as synthetic repellents, it’s a natural, plant-based option that smells great and doesn’t rely on harsh chemicals. When used properly, citronella can be an effective part of your outdoor pest control strategy, helping you enjoy your time outside with fewer buzzing and biting interruptions.
Does Citronella Repel Gnats: FAQs
Q1. How effective is citronella in repelling gnats? Citronella has modest effectiveness in repelling gnats. It works by masking scents that attract gnats and interfering with their ability to locate targets. However, its effectiveness is limited, typically providing protection for only 1-2 hours before reapplication is needed.
Q2. What forms of citronella work best against gnats? Citronella oils and sprays with higher concentrations (10% or more) tend to be more effective than candles or plants. Diffusers and tiki torches can also provide wider coverage. For optimal results, combine citronella with other repellent essential oils like peppermint or eucalyptus.
Q3. How should I use citronella products for maximum effectiveness against gnats? Place citronella sources strategically near entry points and around gathering areas. Create a perimeter using multiple citronella sources. Use fans to help disperse the scent, and reapply citronella-based repellents every 1-2 hours, especially after swimming or sweating.
Q4. Are there any limitations to using citronella as a gnat repellent? Yes, citronella’s effectiveness can be reduced by wind, high temperatures, and rapid evaporation of its active compounds. It also provides shorter protection times compared to synthetic alternatives. Different gnat species may respond differently to citronella, with some potentially being attracted to it.
Q5. Can citronella be combined with other methods for better gnat control? Absolutely. Citronella works best as part of a comprehensive gnat control strategy. Combine it with other natural repellents, ensure proper sanitation to remove gnat breeding sites, use sticky traps, and consider using fans to create air movement that gnats find difficult to navigate.
References
Click to Expand
[1] – http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S1019-91282014000100012
[2] – https://www.ecoshieldpest.com/blogs/does-citronella-work-against-all-insects
[3] – https://www.hineighbor.com/blogs/the-journal/how-to-keep-bugs-away-from-patio?srsltid=AfmBOoqyB11h-2AIObgUHAf-LNQItMrMy5t8FNc4Wc63GIOXV-nVWFjQ
[4] – https://www.researchgate.net/figure/Chemical-Compositions-of-Java-Citronella-Oil-Cymbopogon-winterianus_tbl1_324881520
[5] – https://www.bhg.com/gardening/vegetable/herbs/citronella-plant-care/
[6] – https://pubmed.ncbi.nlm.nih.gov/18437831/
[7] – https://reliantpest.com/10-plants-that-naturally-repel-mosquitoes/
[8] – https://www.today.com/home/how-repel-mosquitoes-summer-do-citronella-candles-really-work-t127599
[9] – https://www.mosquitomax.com/do-citronella-tiki-torches-really-work-to-get-rid-of-mosquitoes/
[10] – https://www.gardendesign.com/plants/mosquito-repellent.html
[11] – https://www.medicalnewstoday.com/articles/325337
[12] – https://www.nature.com/articles/s41598-023-28820-9
[13] – https://www.maximumpestcontrol.ca/pest-control/annoying-gnats-ruining-your-outdoor-fun-can-citronella-help/
[14] – https://www.campingworld.com/pic-bugables-citronella-mosquito-repellent-coil-wristbands-6-pack-738977.html?srsltid=AfmBOoqBQlqa1HxrNDDd0tJLx_H0slZtV4mTSRBwAZIH-FYi-ioH4M2d
[15] – https://htiva.com/three-ways-to-get-rid-of-gnats/
[16] – https://www.researchgate.net/publication/51039980_Effectiveness_of_citronella_preparations_in_preventing_mosquito_bites_Systematic_review_of_controlled_laboratory_experimental_studies
[17] – https://www.researchgate.net/publication/46254778_Efficacy_of_the_Botanical_Repellents_Geraniol_Linalool_and_Citronella_Against_Mosquitoes
[18] – https://www.mdpi.com/2075-1729/13/1/141
[19] – https://www.mdpi.com/2079-6412/12/4/476
[20] – https://www.researchgate.net/publication/24005598_Testing_the_use_of_a_citronella-based_repellent_as_an_effective_method_to_reduce_the_prevalence_and_abundance_of_biting_flies_in_avian_nests
[21] – https://iopscience.iop.org/article/10.1088/1755-1315/739/1/012064/pdf
[22] – https://oiltherapycentral.com/blogs/essential-oils/gnat-gone-essential-oils/
[23] – https://tasty-yummies.com/homemade-essential-oil-insect-repellent-spray/
[24] – https://nikura.com/blogs/essential-oils/citronella-oil-for-mosquito-repellent
[25] – https://lawnlove.com/blog/how-to-get-rid-of-lawn-gnats/
[26] – https://www.gardengatemagazine.com/review/keep-gnats-and-mosquitoes-away-for-good/
[27] – https://www.healthline.com/health/citronella-oil
[28] – https://www.quora.com/Why-do-insect-repellents-need-reapplying-after-a-few-hours
